I am used to using an IDE like Eclipse or Netbeans when coding in Java and having a small code assist appear to give me a small description on each of the methods available. Now code assist does work in Aptana Studio 3 for Ruby on rails, but it does not give you a small description of what the methods do, they just give you a list of the methods only. Is there any IDE or Text based editor that can give me code definition while coding or is there a way to configure Aptana Studio to do so?

As I am new to ruby, I do not want to invest and buy an IDE or Text Based Editor as of yet (though feel free to tell me if the payed ones are the ONLY ones to do what I am asking). I am running Windows 7. But if my only option is to run a VM with Linux so as to get what I am asking than please suggest the name of the IDE or Text-based editor.